New research finds soy can limit growth of Listeria

Soybeans are known for their essential amino acids, high protein content and as a good source of fiber and calcium. But, it turns out, soy also has the ability to naturally protect people from foodborne illnesses such as Listeria.

Recent research from the University of Guelph in Ontario, Canada found soy can limit the growth of some bacteria, such as Listeria and pseudomonas, and it can be more effective than chemical-based agents.

“Current synthetic-based, chemical-based anti-microbial agents kill bacteria indiscriminately, whether they are pathogenic or beneficial,” researcher Suresh Neethirajan said in a recent article. The body – and in particular, the intestines – need good bacteria to properly process the food we eat. The compounds in soybeans, however, do not kill off all bacteria, just the bad ones, Neethirajan continued.

Soybean derivatives are already used in a variety of products including canned foods, cooking oils, meat alternatives, cheeses, ice cream and baked goods.

Neethirajan, an engineering professor and director of the BioNano Laboratory at the university, said those with soy allergies need not worry about soy being used to prevent bacteria growth as their method isolates the active component of the soybean from the protein that causes allergic reactions. The soy isoflavones, chemically similar to estrogen, are also weeded out. What’s left is a compound that naturally stops bad bacteria.

Neethirajan explained in the article that the problem with the synthetic additives that are currently used to kill bacteria is that they can cause health problems since they cannot tell the difference when they come in contact with good versus bad bacteria.

“You do need good bacteria, beneficial bacteria, in our intestines to be able to properly process the food we eat, so that’s why a lot of antibiotic food preservatives, which are made of synthetic chemicals, have side effects such as stomach cramps, diarrhea, bloating, gas,” he said.

“Because of the selective specificity [by soy] towards inhibiting the pathogenic bacteria compared to beneficial bacteria, it will eliminate some of the health issues associated with the current synthetic-based food preservatives,” Neethirajan added. This could be good news for those concerned about additives to their food and also for soybean producers.

Neethirajan is now working to identify which varieties of soybeans are best at preventing bacteria from growing, which he said could help the producers of soybeans choose which varieties they want to grow towards specific end applications.

The article explains that he is also working on a method to extract the specific components that involves “using water at very high pressure to be able to separate these … specific components, so it’s very environmentally friendly from the manufacturing perspective.”